Mine is a Hydrabak which I bought in 2006, it has the foldover velcro closure. Apparently the new version has a slide thingy that closes it up, don't know that that's any better. Mine has never leaked.

I have a small one, I think it's 56 oz? Not sure. And the biggest one, a 100 oz. I have a clip that keeps the feed tube where I want it. There's a little round thing marked "Hydratunes" that has a rubber circle, quartered so you can push something through there. I have NO idea what that thing is for.

I can carry all the stuff I need (that isn't already in my seat bag) in either pack. That's usually the bike lock, keys, id, money, cell phone, and all the little odds and ends. Actually I have some cold medicine and ibuprofen in one of the side pockets, so there's another 8 or 10 grams.

The wide mouth makes it simple to clean and easy to fill up with ice cubes.

I don't understand what the big deal is about having a camelbak style hydration system, I've never had anybody gripe about it in the 13 years since I got my first camelbak. Some people don't like them, some people do, I've never seen anybody get ummmm, overwrought? about it except here.

No one has ever so much as mentioned it on any ride. I never counted, but I've seen lots of people use them (and I ride exclusively road). Some people do, some people don't, what's the problem?

Frankly I'm not all that coordinated and fumbling around for the bottle, popping it open, getting a drink, then popping it closed and trying to get it back in that wire cage, all while I'm riding, is just more work than I want to do. Yup, I'm a klutz. It's way easier for me to turn my head slightly and get a swallow at will, without having to break stride at all. Works for me. Doesn't work for other people. That's ok.

As others have mentioned, I use the frame bottles for sports drink (I can only either get 2 small or 1 small 1 large on there since I mounted my frame pump under the top tube). So that's what I drink when I stop and nosh on the dried fruit or bananas or PB crackers. Then I've got the water on my back.

If you can, it's probably a good idea to try several different paks at an LBS. Some people have said the straps dig in or chafe etc. I've never had that problem with any of the 5 or 6 hydration paks I've ever used. But trying stuff out never hurts, its just I usually buy stuff mail order (I HATE shopping, HATE HATE HATE! - I've been told my extreme hatred of shopping, especially SHOE shopping, which I have solved by simply never wearing any, makes me an Unnatural Woman.)

I'm really happy with hydration systems.

Ummm ,let's see, I've NEVER had my bite valve drag in anything. I'm not sure how that would happen, I've got it clipped quite securely up at the top of the pak, and I don't put the pak down in the dirt.

Ummm, what else - no problem with feeling hot because I'm wearing it, but then heat doesn't get to me nearly as much as NORMAL people. I rode 12 miles in the Alabama summer heat on blacktop without my squeeze bottle (this was the incident that prompted getting the camelbak) because I left it at a SAG stop. With the camelback I'm not going to ride off and leave it because I basically don't take it off, except to scrounge munchies out of it and put it right back on.

I don't know, it's just a matter of personal preference really. If you like 'em, wear 'em, if you don't stick with water bottles, if it looks interesting to you go ahead and give it a try. I swear I've never heard or seen anybody make fun of or get upset over the idea of a camelbak ever, in 13 years, except on here.